# How do you differentiate y=x/(3x-1)?

$y ' = \frac{1 \cdot \left(3 x - 1\right) - x \cdot 3}{3 x - 1} ^ 2 =$
$= \frac{3 x - 1 - 3 x}{3 x - 1} ^ 2 =$
$= - \frac{1}{3 x - 1} ^ 2$
given the function $y = f \frac{x}{g} \left(x\right)$
$y ' = \frac{f ' \left(x\right) g \left(x\right) - f \left(x\right) g ' \left(x\right)}{g \left(x\right)} ^ 2$